Blowpipe lighter



S p 1 H. WLCOWIN ET AL BLOWPIPE LIGHTER Filed Aug. 9,' 1934 a2 3 38 v as'l 4/ z/ INVENT6R HERBERT w. cowm QNYILGOT I IACOESSON ATTORNEY PatentedSept. 14, 1937 UNITED STATES PATENT OFFICE BLOWPIPE LIGHTER ApplicationAugust 9, 1934, Serial No. 739,092

17 Claims.

This invention relates to a fluid fuel burner and more particularly toan improved pilot light for such a burner which will consume a minimumamount of fuel and yet be always ready for lighting the burner.

It is desirable to have available a pilot light for lighting burnerswhen they become extinguished, and it is necessary that such pilotlights remain lighted continuously during intermittent use of theburner. Economy in the amount of fuel consumed by the pilot light isfrequently an important factor, and when this requirement exists it isnecessary to maintain the continuously burning pilot light with as smalla flame as possible. The danger always exists, however, that the smallflame may be extinguished by drafts, and it therefore, becomes necessaryto shield the pilot flame against such drafts. On the other hand, withthe use of some fluid fuels, such as acetylene, restriction by a shieldof the air coming to the pilot burner is a serious handicap sincesufllcient air must be supplied to the pilot light burner when the flameis enlarged for lighting ,the main burner. It is necessary therefore, toshield the flame and at the same time to make sure that sumcient airwill reach the pilot light burner under all conditions of operation.

From the foregoing discussion it will be evident that the invention isparticularly useful in connection with a lighter for blowpipes such asthose employed in welding, cutting or deseaming metals. In the use ofsuch blowpipes one operation after another is performed; but betweensuccessive operations it is highly desirable temporarily to shut oif thewelding or heating gases for the sake of fuel economy.

One object of this invention, therefore, is to provide means forshielding the pilot flame from drafts which may extinguish it, therebypermitting a minimum gas consumption when the main burner is not in use,and at the same time to provide ample air for the enlarged or extendedflame required for lighting the main burner. Another object is theprovision of metering means in the pilot burner construction in order toprevent undue fuel consumption. A further object is the screening of thefuel coming to the metering means and the pilot light nozzle. Still aandthe accompanying drawing which illustrates one embodiment of theinvention, and in which:

Fig. 1 is a broken longitudinal elevation of a blowpipe embodying theinvention;

Fig. 2 is a partial longitudinal mid-section illustrating one form ofthe invention;

Fig. 3 is a partial longitudinal mid-section corresponding to Fig. 2illustrating a variant form of the invention; and

Fig. 4 is a fragmentary cross-section showing certain related parts ofthe blowpipe construction.

The embodiment illustrated in the drawing shows the invention as appliedto an oxy-acetylene blowpipe, but it will be realized that the inventionis applicable to other forms of fluid fuel burners.

In. the drawing there is shown a blowpipe comprising a handle 10, havinga valve body section II at its rear end, together with a lever l2 forcontrolling the heating flame, anda valve knob l3 for controlling thecutting oxygen. A stem section I4 connects the handle ill with a head I5to which is attached a tip I6 in the usual manner.

It is preferred to place the pilot burner close to the underside of thehead I5 at some distance from the end of the nozzle ,in a position toprotect the burner from knocks, heat from cutting and slag. Thus, abracket i1 is carried by the stem H in any convenient manner and is hereshown as being clamped by means of bolts ill to one of the conduits l9comprising the stem M. The bracket IT has a bore 20 through it; and afuel conduit 2| communicates with the bore 20 in the bracket, forinstance, by having the end of the conduit inserted in an enlargedsection 22 of the bore and soldered therein. The fuel conduit 2i may beconnected with any source of fluid fuel and in an acetylene blowpipesuch as that here illustrated, is preferably connected with the sourceof acetylene in the valve body.

The bracket I! has a projection 23 thereon extending generally towardthe far end of the tip 6 of the blowpipe. The bore 20 in the bracketextends through and to the end of this projection, which is bothexternally and internally threaded substantially concentrically with thebore. Thus, acetylene coming to the bracket through the fuel conduit 2|may pass through the bore 20 in the bracket and out of the threaded endof the projection 23 thereof. A pilot light nozzle 24 externallythreaded at one end may be screwed into the internal thread at the endof the projection 23 of the bracket l1, and a substantially axial fuelpassage 25 in the nozzle will thus be brought into communication withthe end of the bore 20 in the bracket from which it will receive theacetylene passing through the bore. There is also provided in the nozzle24 one or 5 more air passages 26 disposed at an angle to the fuelpassages with an external opening or external openings in the surface ofthe nozzle. The axial fuel passage 25 having a'constricted throat 21through which fuel coming to the nozzle must 10 of theair passages 26,an aspirating action will be exerted by the fuel 'upon any air in theair passages 26 which will be mixed with the fuel and projected from theend of the nozzle 24.

Normally, acetylene coming to the pilot light nozzle 24 will berestricted to a minimum quantity to keep the light burning. One meansfor controlling the access of acetylene to the pilot light nozzle isillustrated by the construction shown in Fig. 4. In this arrangementacetylene enters the passages in a valve block 28 through a conduit 28and passes through a bore 30 to a duct 3| at the end of which a valve 32is positioned to control the rate of flow of the acetylene. A valve stem33 connects the valve 32 to a threaded portion 34 which turns incorresponding threads in the valve block 28. The position of the valve32 is adjusted by turning a head 35 having a kerf 36 therein, the headbeing fast to the threaded portion 34, the head 35 having therebeneath awasher of such resiliency that it will maintain contact between theblock 28 and the head 35 for varying positions of the valve 32.Acetylene passing the valve 32 enters a valve chamber 31 and passesthence through a. duct 38 to the fuel conduit 2|. Thus, by turning thehead 35 in one direction the amount of acetylene reaching the pilotlight nozzle 24 will be lessened, whereas turning the head 35 in theother direc- 40 tion will increase the amount of acetylene reaching thepilot light nozzle. It is desirable to adjust the head 35 in such amanner as to provide a minimum amount of acetylene to the nozzle 24 anda minimum length of flame at its end.

A second valve is provided in the valve block 28 for effecting a rush offuel to the pilot light nozzle 24 and thus extending the flame to such alength that it will project in front of the blowpipe nozzle l6 to lightthe gases issuing there- 50 from. This second valve arrangementcomprises a hollow nut 38 having a valve seat 40 at its lower end andbeing adapted to screw into a threaded cavity 4| in the valve block 28.A central passage 42 through the hollow nut 38 connects with the 55 duct38 by means of a. plurality of radial passages 43 extending therefrom toan annular space 44 formed between a recess in the hollow nut 38 and thevalve block 28. The annular space 44 opens into the duct 38. A valve 45,carried by a valve stem 46 which is threaded at the end thereof oppositethe valve 45 and screwed into an annular bushing 41 in a button 48,seats upon the valve seat 40, thereby normally closing the centralpassage 42 against access of fuel from the bore 30. A helical spring 48in the hollow nut 38 bears upon the bushing 47 and tends normally tomaintain the valve 45 in closed position.

When it is desired to use the pilot flame to light the gases issuingfrom the tip Hi, the button 48 7 is pressed inwardly thereby opening thevalve 45 and permitting an inrush of fuel gas which passes into thecentral passage 42 through the radial passages 43 to the annular space44 and through the duct 38 to the fuel conduit 2|. The sudden 75 rush offuel gas passes through the constricted pass immediately before passingthe inner ends' throat 21 and out through the axial fuel passage 25 withgreat velocity. The jet of flame is thus elongated by many times itsoriginal length, and, because of the rate at which it passes through theconstricted throat 21, aspirates a large quantity of air which passesthrough the air passages 26 at an accelerated rate.

As best illustrated in Fig. 1, the pilot light control means ispreferably located in the front handle bushing in sucha position thatthe button 48 may be easily operated by pressure from the thumb of thehand holding the blowpipe.

In order to protect the normally small flame at the end of the nozzle 24there is provided a shield 50, here illustrated as a hollow cylinder.One end of the shield 58 is internally threaded and is of such diameterthat it may be screwed upon the externally threaded end of theprojection 23 on the bracket I]. When the pilot light is used forlighting the gases issuing from the nozzle l6 and the rush of fuel gasis projected from the nozzle 24, it is necessary to supply quickly tothe nozzle a greatly increased volume of air. This is especially thecase where acetylene is used and a cloud of smoke will be formed unlesssumcient air is present. Accordingly, a hole 5| is made in the shield 50opposite the external opening of each air passage 26. Movement of airthrough the holes 5| will not tend to extinguish the flame at the end ofthe nozzle 24 because of the position of the holes in the shield; whichserves to protect the flame at the end of the nozzle 24 in the desiredmanner. However, when the pressure in the air passages 26 is reduced theholes 5| provide means for access of an ample supply of air to thepassages 28.

In order further to restrict the quantity of fluid fuel consumed by thepilot light when not in use a metering orifice may be provided betweenthe supply of fluid fuel and the pilot light nozzle 24. One means ofproviding such a nozzle is to insert between the bracket I1 and thepilot light nozzle 24, a nipple wherein a metering orifice is formed,and such a construction is illustrated in Fig. 3 of the drawing. Asshown in Fig. 3, a nipple 52, having a bore therein internally threadedat one end, is screwed upon the external thread of the bracket H. Thenipple 52 has a metering orifice 53 therein in continuation of the boreand is internally and externally threaded at one end like the projection23. The pilot light nozzle 24 is screwed into the internal thread in theouter end of the nipple 52, and a shield 50 is screwed upon the externalthread at the outer end of the nipple protecting the pilot light nozzle24 as previously described. The resistance provided by the meteringorifice 53 limits the volume of fluid fuel reaching the pilot lightnozzle and requires an appreciable pressure within the bore of thenipple to cause passage of any considerable quantity of fuel through thenozzle.

It has been found that impurities are frequently carried by the fluidfuel. These impurities may be solids or even globules of liquid, and ifallowed to reach the metering orifice or the constricted throat 21 inthe pilot light nozzle will tend to clog its passages and prevent properoperation of the apparatus. Accordingly, one or more screens may beinserted in the bore of the nipple 52, and as here shown two screens 54and 55 are so inserted, the screens themselves being conical in shapeand having their apices pointing in the direction of fuel travel. Thebase edges of the Screens are flared outwardly in the form of annularflanges and are held in place between an interior annular shoulder inthe bore of the nipple and an externally threaded bushing I! screwedinto the internal threading in the nipple 52. The screens 54 and 55 havedifferent conical altitudes thereby providing a space between them sothat the fluid fuel is twice screened before reaching the meteringorifice 53. Clearly, a single screen or more than two screens may beemployed under conditions permitting or requiring such screening.

It is even more likely that extraneous solids may be drawn into thepilot light nozzle 24 through the holes Si in the shield 50 than thatsuch solids may be carried in the fiuid fuel. Accordingly, a screen isprovided covering each hole in the shield. One form of screen for thispurpose is indicated in Fig. 3, wherein a circular screen 51, ofdifferent diameters along its axial extent, is firmly held between anannular shoulder 58 in the shield 50 and the outer surface ofv the pilotlight nozzle 24. The edge of the screen 51 adjacent the end of thenipple 52 may either rest uponthe annular face of the nipple between theexternal and internal threads or may be otherwise attached at thispoint. Thus, air passing through the holes in the shield 5| will beproperly screened before entering the air passages 28 in the pilot lightnozzle 24.

The examples here described and illustrated are presented merely toindicate how the invention may be applied. Other forms of the inventiondiffering in detail but not in principle from that here described will,of course, suggest themselves to those skilled in this art.

We claim:

1. In a blowpipe, a pilot light nozzle. having therein a substantiallyaxial fuel gas passage and an air inlet passage at an angle to the fuelgas passage with an external opening in the surface of said nozzle,means for supp ying said passage with a minimumquantity of gas, meansfor supplying said passage at will with an increased quantity of gas,and a shield for said nozzle, said shield having a hole therein adjacentthe external opening of the air inlet passage in said nozzle, the holein said shield serving to permit additional air easily to reach said airinlet passage upon increase of gas supply.

-2. In a blowpipe, a pilot light nozzle having therein a substantiallyaxial constricted fuel gas passage and an air inlet passage at an angleto the fuel gas passage with an external opening in the surface of saidnozzle, a fuel gas supply con P duit connected with the fuel gas passagein said nozzle, means for supplying saidconduit with a minimum quantityof gas, means for supplying said conduit at will with an increasedquantity of gas, and a conicalscreen having its apex pointing inthedirection of fuel gas travel disposed in said conduit and serving toprotect the constricted fuel gas passage in said nozzle from becomingclogged.

3. In a blowpipe,. a pilot light nozzle having therein a substantiallyaxial constricted fuel gas passage and an air inlet passage at an angleto the fuel gas passage with an external opening in the surface of saidnozzle, a fuel gas supply conduit connected with the fuel gas passage,means for supplying said conduit with a minimum quantity of gas, meansfor supplying said conduit at will with an increased quantity of gas,and a pair of conical screens having their .apices pointing in conduit,said screens having different conical altitudes. said screens serving toprotect the constricted fuel gas passage in said nozzle from be- 7passage with an external opening in the surface of said nozzle, a nipplehaving a fuel metering orifice therein connected to said nozzle andopening into the fuel passage therein, and a conical screen having itsapex pointing in the direction of fuel travel disposed in said nipple onthe pressure side of the fuel metering orifice therein to preventclogging of the orifice by particles in the fuel gas. I

5. In a blowpipe, a pilot light nozzle having therein a substantiallyaxial fuel gas passage and an air inlet passage at an angle to the fuelpassage with an external opening in the surface of said nozzle, meansfor supplying said passage with a minimum quantity of gas, means forsupplying said passage at will with an increased quantity of gas, ashield for said nozzle, said shield having a hole therein adjacent theexternal opening of the air passage'in said nozzle, and a screencovering the hole in said shield, the hole in said shield serving topermit additional air easily to reach said air inlet passage uponincrease of gas supply. u

6. In a fluid fuel burner, a pilot light nozzle having therein asubstantially axial fuel passage and an air inlet passage at an angle tothe fuel passage with an external opening in the surface of said nozzle,a fuel conduit connected with the fuel passage in said nozzle, and aconical screen having its apex pointing in the direction of fuel traveldisposed in said conduit, in combination with a shield for said nozzle,said shield having .a hole therein opposite the external opening of theair inlet passage in said nozzle, and a screen passage with an externalopening in the surface of said nozzle, a nipple having a fuel meteringorifice therein connected to said nozzle and opening into the fuelpassage therein, and a conical screen having its apex pointing in thedirection of fuel travel disposed in said nipple, in combination with ashield for said nozzle said shield having a hole therein opposite theexternal opening of the air passage in said nozzle, and a screencovering the hole in said shield.

8. In a blowpipe, a bracket attached to the forward part'of theblowpipe, a pilot light nozzle carried by said bracket, said nozzlehaving therein a substantially axial fuel passage and an air inletpassage at an angle to the fuel passage with an external opening in thesurface of said nozzle, a shield for said nozzle independently carriedby said bracket, said shield having a hole therein adjacent the externalopening of the air inlet passage in said nozzle, a bore in said bracketcommunicating with the fuel passage in said nozzle, and a fuel conduitcommunicating. with the bore in said bracket.

9. In a blowpipe, a bracket attached to the forward part of theblowpipe, a pilot light nozzle carried by said bracket, said nozzlehaving therein a substantially axial fuel passage and an air inletpassage at an angle to the fuel passage with an external opening in thesurface of said nozzle, a shield for said nozzle independently carriedby said bracket, said shield having a hole therein opposite the externalopening of the air passage in said nozzle, said bracket having a boretherein communicating with the fuel passage in said nozzle, a fuelconduit communicating with the bore in said bracket, and a screencovering the hole in said shield.

10. In a blowpipe, a bracket attached to the forward part of theblowpipe, a nipple attached to said bracket at one end, a pilot lightnozzle attached to said nipple at the other end, said nozzle havingtherein a substantially axial fuel passage and an air inlet passage'atan angle to the fuel passage with an external opening in the surface ofsaid nozzle. a shield for said nozzle independently carried by saidnipple, said shield having a hole therein opposite the external openingof the air inlet passage in said nozzle, a screen covering the hole insaid shield and a conical screen having its apex pointing in thedirection 2 of fuel travel disposed in said nipple.

11. In a blowpipe, a bracket attached to the forward part of theblowpipe, said bracket having a bore therethrough; a fuel conduitconnected to said bracket at one end of the bore there- 25 through; anexternal thread on said bracket substantially concentric with the otherend of the bore; a nipple having a bore internally threaded at one endadapted to screw upon the external thread on said bracket, said nipplealso having 30 a metering orifice therein in continuation of the boreand being internally and externally threaded at its other end; a pilotlight nozzle externally threaded at one end for screwing into saidnipple, said nozzle having therein a substantially 35 axial fuel passageand an air inlet passage at an angle to the fuel passage with anexternal opening in the surface of said nozzle; and a shield for saidnozzle having an internal thread therein screwed upon the externalthread of said nipple,

40 said shield having a hole therein opposite the external opening ofthe air inlet passage in said nozzle.

12. In a blowpipe, a bracket attached to the forward part of theblowpipe, said bracket hav- 5 ing a bore therethrough; a fuel conduitconnected to said bracket at one end of the bore therethrough; anexternal thread on said bracket substantially concentric with the otherend of the bore; a nipple having a bore internally threaded 50 at oneend adapted to screw upon the external thread on said bracket, saidnipple also having a metering orifice therein in continuation of thebore, and being internally and externally threaded at its other end; apilot light nozzle exter- 55 nally threaded at one end for screwing intosaid nipple, said nozzle having therein a substantially axial fuelpassage and an air inlet passage at an angle to the fuel passage with anexternal opening in the surface of said nozzle; and a. shield 0 for saidnozzle having an internal thread therein screwed upon the externalthread of said nipple,

said shield having a hole therein opposite theexternal opening of theair passage in said nozzle; in combination with a conical screen having05 its apex pointing in the direction of fuel travel disposed in thebore of said nipple.

13. In a blowpipe, a bracket attached to the forward part of theblowpipe, said bracket having a,bore therethrough; a fuel conduitconnected 7 to said bracket at one end of the bore therethrough; anexternal thread on said bracket substantially concentric with the otherend of the bore; a nipple having a bore internally threaded at one endadapted to screw upon the external 75 thread on said bracket, saidnipple also having a metering orifice therein in continuation of thebore and being internally and externally threaded at its other end; apilot light nozzle externally threaded at one end for screwing into saidnipple, said nozzle having therein a substantially 5 axial fuel passageand an air inlet passage at an angle to the fuel passage with anexternal opening in the surface of said nozzle; and a shield for saidnozzle having an internal, thread therein screwed upon the externalthread of said nipple, 10 said shield having a hole therein opposite theexternal opening of the air passage in said nozzle;

in combination with apair of conical screens having their apicespointing in the direction of fuel travel disposed in the bore of saidnipple, 5 said screens having diiferent conical altitudes.

14. In a blowpipe, a bracket attached to the forward part of theblowpipe, said bracket having abore therethrough; a fuel conduitconnected to said bracket at one end of the bore therethrough; anexternal thread on said bracket substantially concentric with the otherend of the bore; a nipple having a bore internally threaded at one endadapted to screw upon the external thread on said bracket, said nipplealso having a metering orifice therein in continuation of the bore andbeing internally and externally threaded at its other end; a pilot lightnozzle externally threaded at one end for screwing into said nipple,said nozzle having therein a substantially axial fuel passage and an airinlet passage at an angle to the fuel passage with an external openingin the surface of said nozzle; and a shield for said nozzle having aninternal thread therein screwed upon the external thread of said nipple,said shield having a hole therein opposite the external opening of theair inlet passage in said nozzle; in combination with a conical screenhaving its apex pointing in the direction of fuel travel disposed in thebore of said nipple; and a screen covering the-hole in said shield.

15. In a blowpipe, a bracket attached to the forward part of theblowpipe, said bracket having a bore therethrough; a fuel conduitconnected to said bracket at one end of the bore therethrough; anexternal thread on said bracket substantially concentric with the otherend of the bore; a nipple having a bore internally threaded at one endadapted to screw upon the external thread on said bracket, said nipplealso having a metering orifice therein in continuation of the bore andbeing internally and externally threaded at its other end; a pilot lightnozzle externally threaded at one end for screwing into said nipple,said nozzle having therein a substantially axial fuel passage and an airinlet passage at an angle to the fuel passage with an external openingin the surface of said nozzle; and a shield for said nozzle having aninternal thread therein screwed upon the external thread of said nipple,said shield 00 having a hole therein opposite the external opening ofthe air inlet passage in said nozzle; in combination with. a pair ofconical screens having their apices pointing in the direction of fueltravel disposed in the bore of said nipple, said 5 screens havingdifferent conical altitudes; and a screen covering the hole in saidshield, substantially as described.

16. A blowpipe comprising a handle; a tip; and a stem joining saidhandle and said tip, said 7 stem comprising conduits for fuel gas andcombustion supporting gas; a bracket having a bore therethrough carriedby said stem; and a fuel conduit in said stem connected to one end ofthe bore in said bracket; in combination with a pilot 7 light nozzleconnected to said bracket, said nozzle said bracket; in combination witha pilot light having therein a substantially axial fuel passage nozzleconnected to said bracket. said nozzle havin continuation of the bore insaid bracket and ing therein a substantially axial fuel passage in anair inlet passage at an angle to the fuel pascontinuation of the bore insaid bracket and an 5 sage with an external opening in the surface ofair inlet passage at an angle to the fuel passage 5 said nozzle; and aconical screen having its apex with an external opening in the surfaceof said pointing in the direction of fuel travel screening nozzle; aconical screen having its apex pointing the fuel going to the fuelpassage. in the direction of fuel travel screening the fuel 17. Ablowpipe comprising a handle; a tip; and going to the fuel passage; ashield for said nozzle,

10 astem joining said handle and said tip. said stem said shield havinga hole therein opposite the 10 comprising conduits for fuel gas andcombustion external opening of the air passage in, said nozzle;supporting gas; a bracket having a bore thereand a screen covering thehole in said shield. through carried by said stem; and a fuel conduitHERBERT W. COWIN. in said stem connected to one end of the bore inWILGO'I' J. JACOBSSON.

